Video games, which entail the use of mock shooting devices, are popular and entertaining. These video games are typically comprised of computer software which is run on computing devices, such as home personal computers. However, most computer video games, which entail the use of mock shooting devices typically, use computer peripherals, such as a keyboard, a mouse or a joystick to aim and shoot at visual targets on a computer or video screen. Other similar devices, such as the PLAYSTATION (trademarked) from SONY (trademarked) and the XBOX (trademarked) from MICROSOFT (trademarked), use a game pad or other game control device to aim and shoot at visual targets on a computer video screen. These types of peripheral devices make the shooting games somewhat less realistic.
There have been some attempts to make video games which entail the use of mock shooting devices, more realistic. All known prior art in the field of shooting video games, as described in the U.S. Pat. Nos. 5,366,229 to Suzuki and 6,146,278 to Kobayashi, incorporated herein by reference, rely on three major components: a mock gun that can emit a light beam to a target on a screen to be shot at, a video camera that photographs the screen for detecting an intersecting point of the light beam on the screen, and a position determination device that determines the actual position of the light beam on the screen. The position of the light beam on the screen can then be fed back to shooting video game control computer software to determine if a visual target on a screen is “hit” or not. Some visual and audio feedback signals indicating hit or miss can be generated. Although these systems are more realistic than the shooting video games with keyboards or joysticks, they are not very suitable for use with the shooting video games on computers or similar devices.
The main reason is the fact that a normal video camera used to photograph a computer monitor screen may not be able to provide steady video images of the computer monitor screen due to the difference in frequencies of the monitor and the video camera. The monitor refresh frequency is typically selectable between sixty-one hundred and twenty Hz while the video camera capturing frequency is typically less than thirty Hz. The video camera capturing frequency is also processing speed and image size dependent. Fast computers may be able to capture thirty video frames per second (thirty Hz) with an image size of 640 by 480 pixels. Slow computers may only be able to capture ten frames per second (ten Hz) with the same image size and thirty frames per second for a smaller size of for example 320 by 240 pixels. Only if both frequencies are identical or the monitor refresh frequency divided by the camera capturing frequency is an integer in a more general term, steady video images of the monitor screen may be captured. Since a computer user may use any refresh frequency from a wide range of monitor refresh frequencies and most video cameras have a typical capturing frequency of between ten and thirty Hz, it is very common that video cameras do not provide steady video images from a computer monitor due the frequency mismatch.
For capturing a steady video from a computer monitor, there are only two options. The first option involves very high-end video cameras with special auto-sync functions. Although they can in general provide steady video images from most computer monitors, they are very expensive. The second option is to preset the computer monitor refresh frequency to say sixty Hz or seventy-five Hz to keep the needed synchronization with the typical video camera with say thirty Hz or twenty-five Hz, respectively. However, this is only a valid option if the same manufacturer ships the video camera and the computer monitor used by the shooting video game and computer users do not modify the refresh frequency of their computer monitor. Because video cameras, computers, monitors and video games in general are not from a single vendor or manufacturer and computer users very often do modify the refresh frequency of their monitors, this second option is very often not practical.
In addition to the frequency mismatch problem mentioned above, the camera in the prior art as described in the U.S. Pat. No. 5,366,229, incorporated by reference herein, must be placed somewhere near a game player and facing the same orientation as the game player for capturing the display screen. Although this may not present a serious problem in a professionally designed game playing place, it could be very challenging to place the video camera at home in such a way that it may not easily be occluded at anytime during the game and may not easily be bumped into. This is not always practical. In order to solve the difficult camera placement problem, the camera as described in the U.S. Pat. No. 6,146,278, incorporated herein by reference, are integrated with the mock shooting device so that the camera is always facing the target screen without the danger of occlusion. However, this arrangement makes the mock shooting device somewhat expensive and the integrated video camera totally single-purposed. Furthermore, the mock shooting device with the camera must be connected to the computing device directly via a cable, which may also cause inconvenience when playing.
The above mentioned drawbacks, namely, the frequency mismatch between the display screen and the low-cost video camera, the difficult placement of the video camera facing the screen, relatively high cost for a mock shooting device with an integrated camera, as well as a needed connection cable between the mock shooting device and the computing device, can seriously limit the applicability of the prior art techniques for game players who want to play realistic video shooting games with their computers at home.